The Angry Breed (1968)

In Vietnam, Johnny Taylor, an aspiring actor, saves a Hollywood screenwriter's life and is rewarded with a coveted film script. Back home, he struggles to land a lead role until he heroically rescues producer Vance Patton's daughter, Diane, from a gang assault. Grateful, Patton connects him with agent Mori Thompson, who, however, schemes to use the script for gang leader Deek Stacy. As the Halloween party unfolds, Deek and his agent slip Johnny LSD and imprison him in a dungeon, setting the stage for a gripping tale of ambition and danger.